Question

goal: to demonstrate student understanding of independent and dependent variables. date: period: procedure - part i: identify the dependent and independent variable in each of the eight investigations below. remember the following definitions: independent variable the factor manipulated (or changed) by the scientist. this might also be described as the change made by the experimenter on purpose. dependent variable the factor (or result) which changes because of what the scientist does. the dependent variable is the change that occurs because of what the experimenter does; it gets changed by the independent variable. it is sometimes called the responding variable. this is the variable that the scientist measures because it is changed as a result of the iv. example: you are investigating how soil type influences bean stem growth. in your investigation... a. independent - variable (the variable that you are changing) is types of soil used. b. dependent - variable (the results) would be the growth of bean stems. 1. is plant growth affected by the color of light in which it grows? a. independent variable: b. dependent variable: c. some controlled variables: 2. which laundry detergent removes stains more effectively? a. independent variable: b. dependent variable: c. some controlled variables: 3. does the type of oil affect the size of popcorn? a. independent variable: b. dependent variable: c. some controlled variables: 4. which type of paper towel is more absorbent? a. independent variable: b. dependent variable: c. some controlled variables: 5. which battery has the longest life - span? a. independent variable: b. dependent variable: c. some controlled variables: 6. which paint resists weathering more effectively? a. independent variable: b. dependent variable: c. some controlled variables: 7. do different types of music affect student math accuracy? a. independent variable: b. dependent variable: c. some controlled variables: 8. how do different salts affect the melting point of ice? a. independent variable: b. dependent variable: c. some controlled variables:

Explanation:

1.
a. The independent variable is the color of light as it is what the experimenter changes.
b. The dependent variable is plant growth as it is the result that changes due to the independent variable.
c. Controlled variables could be plant type, soil type, amount of water, temperature.
2.
a. The independent variable is the type of laundry detergent as it is manipulated by the experimenter.
b. The dependent variable is the effectiveness of stain - removal as it is the result measured.
c. Controlled variables could be the type of stain, fabric type, water temperature, amount of detergent.
3.
a. The independent variable is the type of oil as it is the factor being changed.
b. The dependent variable is the size of popcorn as it is the outcome of the change.
c. Controlled variables could be popcorn kernel type, popping time, heat source.
4.
a. The independent variable is the type of paper towel as it is what is being varied.
b. The dependent variable is absorbency as it is the measured result.
c. Controlled variables could be amount of liquid, type of liquid, area of paper towel exposed.
5.
a. The independent variable is the type of battery as it is what is being compared.
b. The dependent variable is battery life - span as it is the result being measured.
c. Controlled variables could be the device the battery is used in, usage pattern, temperature.
6.
a. The independent variable is the type of paint as it is the factor being changed.
b. The dependent variable is weather - resistance as it is the outcome.
c. Controlled variables could be surface type, exposure area, location.
7.
a. The independent variable is the type of music as it is what is being manipulated.
b. The dependent variable is student math accuracy as it is the result measured.
c. Controlled variables could be student age, math topic, time given for the test.
8.
a. The independent variable is the type of salt as it is the factor being changed.
b. The dependent variable is the melting point of ice as it is the result measured.
c. Controlled variables could be ice quantity, starting temperature, container type.

Answer:

1.
a. Color of light
b. Plant growth
c. Plant type, soil type, amount of water, temperature
2.
a. Type of laundry detergent
b. Effectiveness of stain - removal
c. Type of stain, fabric type, water temperature, amount of detergent
3.
a. Type of oil
b. Size of popcorn
c. Popcorn kernel type, popping time, heat source
4.
a. Type of paper towel
b. Absorbency
c. Amount of liquid, type of liquid, area of paper towel exposed
5.
a. Type of battery
b. Battery life - span
c. Device the battery is used in, usage pattern, temperature
6.
a. Type of paint
b. Weather - resistance
c. Surface type, exposure area, location
7.
a. Type of music
b. Student math accuracy
c. Student age, math topic, time given for the test
8.
a. Type of salt
b. Melting point of ice
c. Ice quantity, starting temperature, container type